A priori, no investment is "rational." That is, was the construction of 100,000 tanks to export the Communist revolution a rational investment by the Soviet Union? How about the $2 billion in private equity that went into building Facebook, a system designed to let people "like" their friends? The point of a free market is that many experiments are run in parallel. Some of these are deemed rational via feedback. Some fail, and are deemed irrational. A free market is not more rational than a planned economy; however, unlike a planned economy, a free market isn't dependent on a single plan.